Described embodiments include a system for updating amesh, which includes a plurality of vertices, representing asurface of a heart. The system includes an electricalinterface and a processor. The processor is configured todefine a plurality of sample points on the mesh, such that adensity of the sample points is greater than a density of thevertices, to receive, via the electrical interface, aplurality of signals from a catheter, the signals indicatingan electrical property of each of a plurality of locations onthe surface, and to update the mesh in accordance with theelectrical property, by, for each of the locations,identifying a closest sample point to the location,subsequently, identifying, in a portion of the mesh in whichthe closest sample point is located, a closest point to thelocation, and, subsequently, associating the closest pointwith the electrical property of the location.
